Disperse azo dyestuffs containing a thiocyonate group

ABSTRACT

Water-insoluble dyestuffs of the formula I ##STR1## wherein K denotes the radical of a coupling component of the aniline series, 
     X denotes Cl, Br, Cn or COOZ, 
     Y denotes H, Cl, Br or CN and 
     Z denotes C 1  -C 4  -alkyl, 
     are outstandingly suitable for dyeing polyester fibres, on which they produce brilliant dyeings with good general fastness properties.

The invention relates to disperse azo dyestuffs of the formula I ##STR2## wherein K denotes the radical of a coupling component of the aniline series,

X denotes Cl, Br, CN or COOZ,

Y denotes H, Cl, Br or CN and

Z denotes C₁ -C₄ -alkyl.

Preferred dyestuffs correspond to the formula II ##STR3## wherein--independently of one another-- R₁ is H, OH, Z, OZ, Cl, COOZ, CONH₂ or NHAc,

R₂ is H, Cl, Z, OZ or COOZ and

R₃ are H, Z or C₂ -C₅ -alkyl which is optionally substituted by CN, Cl, OH, OZ, COOZ, OCOZ, OCOOZ or phenyl,

wherein

X, Y and Z have the abovementioned meaning and

Ac represents an acyl radical from the series comprising COZ, SO₂ Z, COOZ and CONH₂.

Particularly preferred dyestuffs are those of the formulae I or II wherein

X denotes COOZ or CN,

Y denotes H or Cl,

R₁ denotes CH₃, NHCOZ or SO₂ Z,

R₂ denotes H and

R₃ and R₄ denote Z, or C₂ -C₄ -alkyl which is optionally substituted by CN, OZ, OCOZ or, wherein Z is as defined above.

Amongst these dyestuffs, those which are in turn preferred are the dyestuffs of the formulae shown wherein

X represents CN.

Especially preferred dyestuffs are those of the formulae I and II wherein

X, Y, Z and R₂ have the abovementioned meanings,

R₁ denotes NHCOZ and

R₃ =R₄ and both denote C₂ H₄ OZ.

Z in particular represents CH₃ or C₂ H₅ in these dyestuffs.

The new dyestuffs are preferably obtained by a process in which diazotized amines of the formula III ##STR4## are coupled to coupling components of the formula IV

    K--H                                                       (IV)

in the customary manner.

The diazotization is preferably carried out by means of nitrosylsulphuric acid in glacial acetic acid/phosphoric acid mixtures.

Both the diazotization and the coupling can be carried out in the presence of water-miscible organic solvents, dispersing or wetting agents and emulsifiers.

The addition of seed crystals is occasionally advisable.

Suitable solvents are C₁ -C₄ -alcohols, glycols, glycol ethers, dialkyl ethers, esters and ketones.

Dyestuffs of the formula ##STR5## wherein X and/or Y denote cyano can advantageously also be prepared from the corresponding halogenoazo dyestuffs (X/Y=Cl or Br) by reaction with cyanides.

Such halogen/cyano exchange reactions have been described in many instances in the literature (compare, for example, U.S. Pat. No. 3,962,209).

Only some of the amines of the formula III are known. They can easily be prepared by methods which are known per se, for example by introducing the thiocyano group into aromatic amines of the formula IV ##STR6## using bromine and alkali metal thiocyanates in aqueous or organic or aqueous-organic solvents, such as methanol, glacial acetic acid or propionic acid, if appropriate with the addition of mineral acids, such as HBr or H₃ PO₄ (compare "Pharmazie", 32, 195-215 (1977)).

The dyestuffs of the formula I or II are suitable for dyeing polyester materials in orange, red and violet shades. The dyeings are distinguished by brilliance, depth of colour, fastness to light and good fastness to thermomigration.

Dyestuffs of the formula I or II are also suitable for textile and non-textile thermal transfer printing. These printing processes are also generally known.

In the following examples, "parts" denote parts by weight.

Examples EXAMPLE 1

9 parts of methyl 2-amino-5-thiocyanato-benzoate are diazotized with 7.5 parts of nitrosylsulphuric acid in a mixture of 60 parts of glacial acetic acid and 20 parts of propionic acid at 0°-5° C. The solution of the diazonium salt is added to a mixture of 9.1 parts of N-ethyl-N-(2-cyanoethyl)-3-methylaniline, 0.5 part of amidosulphonic acid, 50 parts of glacial acetic acid and 100 parts of ice and the coupling is brought to completion by addition of 12 parts of 30% strength sodium hydroxide solution. The dyestuff of the formula ##STR7## which initially separates out in resinous form crystallizes after prolonged stirring. The absorbtion spectrum of the dyestuff recorded in dimethylformamide has a maximum at 452 nm. The dyestuff dyes polyethylene terephthalate fibres (PE) in clear orange-coloured shades of good fastness to light, wet processing and sublimation.

The dyestuffs of the formula V are obtained analogously:

    __________________________________________________________________________      ##STR8##                                    (V)                                                                 λ.sub.max                             No.                                                                               Z  R.sub.1                                                                               R.sub.2                                                                            R.sub.3 R.sub.4  in nm                                                                              Colour shade on PE                       __________________________________________________________________________     2  C.sub.4 H.sub.9                                                                   H      H   C.sub.3 H.sub.7                                                                        C.sub.2 H.sub.4COOCH.sub.3                                                              440 golden yellow                            3  C.sub.2 H.sub.5                                                                   CH.sub.3                                                                              H   C.sub.4 H.sub.9                                                                        C.sub.2 H.sub.4CN                                                                       454 orange                                   4  CH.sub.3                                                                          NHCOCH.sub.3                                                                          H   C.sub.3 H.sub.7                                                                        C.sub.3 H.sub.7                                                                         493 scarlet                                  5  CH.sub.3                                                                          NHCO.sub.2 H.sub.5                                                                    H   C.sub.2 H.sub.4 OCOCH.sub.3                                                            C.sub.2 H.sub.4 OCOCH.sub.3                                                             466 orange                                   6  C.sub.2 H.sub.5                                                                   NHCOC.sub.4 H.sub.9                                                                   OCH.sub.3                                                                          C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.4CN                                                                       495 scarlet                                  7  CH.sub.3                                                                          CH.sub.3                                                                              H   CH.sub.3                                                                               C.sub.2 H.sub.4CN                                                                       450 orange                                   8  CH.sub.3                                                                          NHCOCH.sub.3                                                                          H   C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.4CN                                                                       468 orange                                   9  C.sub.2 H.sub.5                                                                   NHCOCH.sub.3                                                                          H   C.sub.2 H.sub.4 COOCH.sub.3                                                            C.sub.2 H.sub.4 COOCH.sub.3                                                             462 orange                                   __________________________________________________________________________

The diazo components used in these examples were prepared by introducing the thiocyano group into the corresponding anthranilic acid esters by the process described by Neu in the journal Pharmazie 3 (1948) 151.

EXAMPLE 10

15.9 parts of 2,5-dichloro-4-thiocyanato-aniline are diazotized with 13.2 parts of nitrosylsulphuric acid in a mixture of 35 parts of concentrated H₂ SO₄ and 13 parts of 85% strength H₃ PO₄ at 0°-5° C.

The solution of the diazonium salt is added dropwise to a mixture of 15 parts of N-butyl-N-(2-cyanoethyl)-3-methylaniline, 100 parts of methanol, 0.5 part of amidosulphonic acid and 250 parts of ice and the coupling is brought to completion by dropwise addition of 100 parts of 30% strength sodium hydroxide solution.

27.5 parts of the dyestuff ##STR9## .sub.λmax 451 nm (DMF), which dyes polyester fibres in orange-coloured shades of good fastness to light, are obtained.

The dyestuffs of the formula VI ##STR10## are obtained analogously.

    __________________________________________________________________________                             λ.sub.max                                       No.                                                                               R.sub.2                                                                          R.sub.3                                                                               R.sub.4                                                                              R.sub.5                                                                              nm  Colour shade on PE                                 __________________________________________________________________________     11 H CH.sub.3                                                                              C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                      468 orange                                             12 H CH.sub.3                                                                              C.sub.4 H.sub.9                                                                      C.sub.2 H.sub.4 OCO.sub.3                                                            457 orange                                             13 H NHSO.sub.2 CH.sub.3                                                                   C.sub.2 H.sub.4 OCH.sub.3                                                            C.sub.2 H.sub.4 OCH.sub.3                                                            484 reddish-tinged orange                              14 H NHCOCH.sub.3                                                                          C.sub.3 H.sub.7                                                                      C.sub.3 H.sub.7                                                                      512 yellowish-tinged red                               15 H NHCOCH.sub.3                                                                          C.sub.2 H.sub.4 OCH.sub.3                                                            C.sub.2 H.sub.4 OCH.sub.3                                                            508 yellowish-tinged red                               __________________________________________________________________________

EXAMPLE 16

7.6 parts of 2-amino-5-thiocyanato-benzonitrile are diazotized in aqueous hydrochloric acid at 0°-5° C. and the solution is clarified and combined with a solution of 13.2 parts of 3-[-(bis-2-methoxyethyl)amino]acetanilide in aqueous hydrochloric acid. The coupling must be brought to completion by addition of 30% strength sodium hydroxide solution at 0°-5° C. The dyestuff which initially separates out in resinous form becomes crystalline after prolonged stirring. It corresponds to the formula ##STR11## .sub.λmax 515 nm (DMF) and dyes polyester materials in clear red shades of very good fastness to light, sublimination, wet processing and thermomigration.

The dyestuffs of the formula VII ##STR12## are obtained analogously.

    __________________________________________________________________________                                   λ.sub.max                                 No.                                                                               Y R.sub.1                                                                               R.sub.2                                                                            R.sub.3                                                                               R.sub.4                                                                               in nm                                                                              Colour shade on PE                           __________________________________________________________________________     17 H NHCOCH.sub.3                                                                          H   C.sub.2 H.sub.5                                                                       C.sub.2 H.sub.5                                                                       520 red                                          18 H NHCOCH.sub.3                                                                          H   OCOCH.sub.3                                                                           OCOCH.sub.3                                                                           519 red                                          19 H CH.sub.3                                                                              H   C.sub.4 H.sub.9                                                                       C.sub.2 H.sub.4 CN                                                                    493 reddish-tinged orange                        20 H NHCOCH.sub.3                                                                          OCH.sub.3                                                                          C.sub.2 H.sub.5                                                                       C.sub.2 H.sub.4 CN                                                                    533 ruby                                         21 H NHCOC.sub.3 H.sub.7                                                                   Cl  H      C.sub.2 H.sub.4 OCH.sub.3                                                             492 reddish-tinged orange                        22 H NHSO.sub.2 CH.sub.3                                                                   H   C.sub.2 H.sub.5                                                                       C.sub.2 H.sub.5                                                                       512 red                                          23 H NHCOCH.sub.3                                                                          Cl  H      C.sub.2 H.sub.4 OH                                                                    498 scarlet                                      24 Br                                                                               NHCOCH.sub.3                                                                          OCH.sub.3                                                                          C.sub.2 H.sub.5                                                                       C.sub.2 H.sub.5                                                                       592 reddish-tinged blue                          25 H NHCOCH.sub.3                                                                          H   C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                      C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                      516 red                                          26 H NHCOC.sub.2 H.sub.5                                                                   H   C.sub. 2 H.sub.4 OCH.sub.3                                                            C.sub.2 H.sub.4 OCH.sub.3                                                             515 red                                          __________________________________________________________________________

The 2-amino-5-thiocyanato-benzonitrile used in these examples can be prepared as follows:

200 parts of bromine are slowly added to

118 parts of 2-aminobenzonitrile and

123 parts of sodium thiocyanate in

300 parts of glacial acetic acid and

150 parts of 85% strength orthophosphoric acid at about 10° C.

The reaction mixture is poured onto 500 parts of ice-water, and 150 parts of 30% strength sodium hydroxide solution are allowed to run in. The crystalline precipitate is filtered off with suction, washed and dried. About 155 parts of crude product (melting point 116° C.), which can be employed for dyestuff synthesis in this form or the non-crystallized form, are obtained. It is contaminated with small amounts of 2-amino-5-bromo-benzonitrile.

EXAMPLE 27

6.1 parts of 2-amino-5-thiocyanato-6-chlorobenzonitrile are diazotized with 5 parts of nitrosylsulphuric acid in 40 parts of glacial acetic acid and 15 parts of propionic acid at -5-0° C.

The diazonium salt solution thus obtained is introduced into a cold (0° C.) solution of 5.8 parts of 1-(m-tolyl)-3,5,5-trimethylpyrazoline in 40 parts of glacial acetic acid and 20 parts of propionic acid such that the temperature does not rise above 5° C.

After 30 minutes, the product is precipitated with 50-70 parts of water, isolated, washed and dried.

9 parts of the dyestuff of the formula VIII ##STR13## (.sub.λmax (DMF) 536 nm), which dyes polyester in red-violet shades of good fastness to wet processing and thermomigration, are obtained.

The dyestuffs of the formula IX ##STR14## are obtained analogously.

    __________________________________________________________________________                                       λ.sub.max                                                                   Colour shade                             No.                                                                               R.sub.1                                                                              R.sub.2                                                                            R.sub.3  R.sub.4     in nm                                                                              on PE                                    __________________________________________________________________________     28 NHCOCH.sub.3                                                                         OCH.sub.3                                                                          C.sub.2 H.sub.4 OCH.sub.3                                                               C.sub.2 H.sub.4 OCH.sub.3                                                                  554 red-violet                               29 CH.sub.3                                                                             H   C.sub.2 H.sub.5                                                                          ##STR15##  520 yellow-tinged red                        30 NHCOCH.sub.3                                                                         H   C.sub.2 H.sub.4 OCH.sub.3                                                               C.sub.2 H.sub.4 OCH.sub.3                                                                  526 bluish-tinged                                                                  red                                      31 CH.sub.3                                                                             H   CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3                                                     C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                           522 red                                      32 CH.sub.3                                                                             H   C.sub.2 H.sub.5                                                                          ##STR16##    514.8                                                                            yellowish-tinged red                     33 CH.sub.3                                                                             H   C.sub.2 H.sub.5                                                                          ##STR17##  516 yellowish-tinged red                     34 CH.sub.3                                                                             H   C.sub.2 H.sub.5                                                                         C.sub.2 H.sub.5                                                                            523 red                                      __________________________________________________________________________

The 2-amino-5-thiocyanato-6-chloro-benzonitrile used in Examples 27-34 can be prepared as follows:

40 parts of 2-amino-6-chloro-benzonitrile are introduced into 100 parts of glacial acetic acid and 40 parts of propionic acid. 53 parts of potassium thiocyanate are added and the mixture is cooled to 0° C. 43 parts of bromine are added dropwise in the course of 2 hours, during which the temperature should not rise above 5° C. After 2 hours, the mixture is warmed to 20° C. and poured onto 300 parts of ice/water, and the product is isolated and dried. The product thus obtained (melting point 136°-145° C.) contains small amounts of brominated amines. It can be used for dyestuff synthesis by recrystallization from dimethylformamide/water or in nonpurified form. 

We claim:
 1. A disperse azo dyestuff of the formula (II) ##STR18## wherein X denotes CN or COOZY denotes H, Cl, Br or CN Z denotes C₁ -C₄ -alkyl,and, independently of one another, R₁ represents H, OH, Z, OZ, Cl, COOZ, CONH₂ or NHAc, R₂ represents H, Cl, Z, OZ, or COOZ and R₃ and R₄ represent Z or C₂ -C₅ -alkyl, which is optionally substituted by CN, Cl, OH, OZ, COOZ, OCOOZ, or phenyl,wherein Ac represents an acyl radical from the series comprising COZ, SO₂ Z, COOZ and CONH₂.
 2. A dyestuff according to claim 1, characterized in thatX denotes COOZ or CN, Y denotes H or Cl, R₁ denotes CH₃, NHCOZ or NHSO₂ Z, R₂ denotes H and R₃ and R₄ represent Z or C₂ -C₄ -alkyl, which is optionally substituted by CN or OZ, and Z has the meaning given in claim
 1. 3. A dyestuff according to claim 1, characterized in that X represents CN.
 4. A dyestuff according to claim 1, characterized in thatR₁ denotes NHCOZ and R₃ =R₄ and both denote C₂ H₄ OZ.
 5. A dyestuff of the formula ##STR19## .
 6. Process for dyeing and printing polyester materials, characterized in that dyestuffs according to anyone of claims 1 to 5 are used. 